In my U.S. Pat. No. 3,233,882, I disclose spray devices for use in combination with a cyclonic gas-scrubber where these spray devices, each comprising several spray nozzles, could be attached to the exterior of the tower at locations having corresponding openings. The principal advantage of this construction lies in the fact that the spray nozzles can be more or less readily detached from the exterior of the tower for cleaning and for replacement if necessary. However, the fact that such nozzles eventually wear and require replacement constitutes a substantial disadvantage. Moreover, the number of nozzles required to effect both injection of an adequate quantity of liquid and satisfactory dispersion of the liquid is relatively large. Further, spray nozzles do not generally permit recirculation of slurry solution without the hazard of plugging. In addition, the problem of sealing the nozzles against the exterior of the tower to prevent leakage of gas through the openings in the tower is substantial and involves a cost which is not negligible, the cost including relatively complex components and the labor of maintenance and installation. Accordingly, a simpler construction which avoids the above difficulties and costs is greatly to be desired.